Implementation phase, description

This section shall contain a general description of the WAN. It may describe, eventually, different implementation phases of the WAN, the interconnection points, and their geographic location. This section shall contain the following information ... 

Description of generic principles used for the development of the EOFs. Also, during the documentation and implementation phase additional representative analyses may be incorporated to augment staff and operator training. These best estimate analyses include operator actions, as they are required in the EOFs. 

There are two problems in the manufacture of PS removal of the heat of polymeriza tion (ca 700 kj /kg (300 Btu/lb)) of styrene polymerized and the simultaneous handling of a partially converted polymer symp with a viscosity of ca 10 mPa(=cP). The latter problem strongly aggravates the former. A wide variety of solutions to these problems have been reported for the four mechanisms described earlier, ie, free radical, anionic, cationic, and Ziegler, several processes can be used. Table 6 summarizes the processes which have been used to implement each mechanism for Hquid-phase systems. Free-radical polymerization of styrenic systems, primarily in solution, is of principal commercial interest. Details of suspension processes, which are declining in importance, are available (208,209), as are descriptions of emulsion processes (210) and summaries of the historical development of styrene polymerization processes (208,211,212). 

An Eulerian-Eulerian (EE) approach was adopted to simulate the dispersed gas-liquid flow. The EE approach treats both the primary liquid phase and the dispersed gas phase as interpenetrating continua, and solves a set of Navier-Stokes equations for each phase. Velocity inlet and outlet boundary conditions were employed in the liquid phase, whilst the gas phase conditions consisted of a velocity inlet and pressure outlet. Turbulence within the system was account for with the Standard k-e model, implemented on a per-phase basis, similar to the recent work of Bertola et. al.[4]. A more detailed description of the computational setup of the EE method can be found in Pareek et. al.[5]. 

For the discrete bubble model described in Section V.C, future work will be focused on implementation of closure equations in the force balance, like empirical relations for bubble-rise velocities and the interaction between bubbles. Clearly, a more refined model for the bubble-bubble interaction, including coalescence and breakup, is required along with a more realistic description of the rheology of fluidized suspensions. Finally, the adapted model should be augmented with a thermal energy balance, and associated closures for the thermophysical properties, to study heat transport in large-scale fluidized beds, such as FCC-regenerators and PE and PP gas-phase polymerization reactors. 

In the MQC mean-field trajectory scheme introduced above, all nuclear DoF are treated classically while a quantum mechanical description is retained only for the electronic DoF. This separation is used in most implementations of the mean-field trajectory method for electronically nonadiabatic dynamics. Another possibility to separate classical and quantum DoF is to include (in addition to the electronic DoF) some of the nuclear degrees of freedom (e.g., high frequency modes) into the quantum part of the calculation. This way, typically, an improved approximation of the overall dynamics can be obtained—albeit at a higher numerical cost. This idea is the basis of the recently proposed self-consistent hybrid method [201, 202], where the separation between classical and quantum DoF is systematically varied to improve the result for the overall quantum dynamics. For systems in the condensed phase with many nuclear DoF and a relatively smooth distribution of the electronic-vibrational coupling strength (e.g.. Model V), the separation between classical and quanmm can, in fact, be optimized to obtain numerically converged results for the overall quantum dynamics [202, 203]. 

For materials in the condensed phase, the orbital implementation of the KT -when based on an atomistic description - overestimates in general the values of Se relative to experiment in the low and intermediate projectile velocity region. Since the KT is based on the binary encounter approach, this result is expected since the electronic states in a solid are mainly of a collective character and cannot be fully described by local atomic properties. However, the orbital implementation of the KT may be adapted for sohd targets by introducing band states instead of atomic states. 

In the case of matter under high pressure, although its description corresponds more closely to the condensed phase, an atomistic view based on the orbital implementation of the KT renders useful information on the effects of pressure on stopping. We have shown here that this theory together with the TFDW density-functional method adapted to atomic confinement models allows for the estimate of pressure effects on stopping, as well as for stopping due to free-atoms. 

A detailed description of how Operation Purple developed, its activities and the results achieved in phase I are presented in the 1999 report of the Board on the implementation of article 12 of the 1988 Convention (United Nations publication. Sales No. E.00.XI.3). The activities undertaken during the initial stages of phase II are presented in the 2000 report of the Board on the implementation of article 12 (United Nations publication. Sales No. E.01.X1.4). The objectives of the operation, the procedural details and its results can further be found in the report on phase I of the operation prepared by the Steering Committee. 

Basically, DESIGNER can use different physical property packages that are easy to interchange with commercial flowsheet simulators. For the case considered, the vapor-liquid equilibrium description is based on the UNIQUAC model. The liquid-phase binary diffusivities are determined using the method of Tyn and Calus (see Ref. 72) for the diluted mixtures, corrected by the Vignes equation (57), to account for finite concentrations. The vapor-phase diffusion coefficients are assumed constant. The reaction kinetics parameters taken from Ref. 202 are implemented directly in the DESIGNER code. 

Throughout this chapter, two-phase flows are treated like mono-disperse sprays, an assumption which is not mandatory in EE methods but which makes their implementation easier. Results also suggest that in many flows, this assumption is reasonable. Considering the lack of information on size distribution at an atomizer outlet in a real gas turbine, this assumption might be a reasonable compromise in terms of complexity and efficiency tracking multi-disperse sprays with precision makes sense only if the spray characteristics at the injection point are well known. In most cases, droplets are not yet formed close to the atomizer outlet anyway and even the Lagrange description faces difficulties there. 

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